Hi Michal, -----Original Message----- From: Michal Simek [mailto:michal.simek@xxxxxxxxxx] Sent: Thursday, November 27, 2014 8:17 PM To: Appana Durga Kedareswara Rao; wg@xxxxxxxxxxxxxx; mkl@xxxxxxxxxxxxxx; Michal Simek; Soren Brinkmann; grant.likely@xxxxxxxxxx; robh+dt@xxxxxxxxxx Cc: linux-can@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; Appana Durga Kedareswara Rao Subject: Re: [PATCH v3] can: Convert to runtime_pm On 11/27/2014 02:08 PM, Kedareswara rao Appana wrote: > Instead of enabling/disabling clocks at several locations in the > driver, use the runtime_pm framework. This consolidates the actions > for runtime PM in the appropriate callbacks and makes the driver more > readable and mantainable. > > Signed-off-by: Soren Brinkmann <soren.brinkmann@xxxxxxxxxx> > Signed-off-by: Kedareswara rao Appana <appanad@xxxxxxxxxx> > --- > Changes for v3: > - Converted the driver to use runtime_pm. > Changes for v2: > - Removed the struct platform_device* from suspend/resume > as suggest by Lothar. > > drivers/net/can/xilinx_can.c | 119 > +++++++++++++++++++++++++---------------- > 1 files changed, 72 insertions(+), 47 deletions(-) > > diff --git a/drivers/net/can/xilinx_can.c > b/drivers/net/can/xilinx_can.c index 8a998e3..1be28ed 100644 > --- a/drivers/net/can/xilinx_can.c > +++ b/drivers/net/can/xilinx_can.c > @@ -32,6 +32,7 @@ > #include <linux/can/dev.h> > #include <linux/can/error.h> > #include <linux/can/led.h> > +#include <linux/pm_runtime.h> > > #define DRIVER_NAME "xilinx_can" > > @@ -138,7 +139,7 @@ struct xcan_priv { > u32 (*read_reg)(const struct xcan_priv *priv, enum xcan_reg reg); > void (*write_reg)(const struct xcan_priv *priv, enum xcan_reg reg, > u32 val); > - struct net_device *dev; > + struct device *dev; > void __iomem *reg_base; > unsigned long irq_flags; > struct clk *bus_clk; > @@ -842,6 +843,13 @@ static int xcan_open(struct net_device *ndev) > struct xcan_priv *priv = netdev_priv(ndev); > int ret; > > + ret = pm_runtime_get_sync(priv->dev); > + if (ret < 0) { > + netdev_err(ndev, "%s: runtime CAN resume failed(%d)\n\r", > + __func__, ret); > + return ret; > + } > + > ret = request_irq(ndev->irq, xcan_interrupt, priv->irq_flags, > ndev->name, ndev); > if (ret < 0) { > @@ -849,29 +857,17 @@ static int xcan_open(struct net_device *ndev) > goto err; > } > > - ret = clk_prepare_enable(priv->can_clk); > - if (ret) { > - netdev_err(ndev, "unable to enable device clock\n"); > - goto err_irq; > - } > - > - ret = clk_prepare_enable(priv->bus_clk); > - if (ret) { > - netdev_err(ndev, "unable to enable bus clock\n"); > - goto err_can_clk; > - } > - > /* Set chip into reset mode */ > ret = set_reset_mode(ndev); > if (ret < 0) { > netdev_err(ndev, "mode resetting failed!\n"); > - goto err_bus_clk; > + goto err_irq; > } > > /* Common open */ > ret = open_candev(ndev); > if (ret) > - goto err_bus_clk; > + goto err_irq; > > ret = xcan_chip_start(ndev); > if (ret < 0) { > @@ -887,13 +883,11 @@ static int xcan_open(struct net_device *ndev) > > err_candev: > close_candev(ndev); > -err_bus_clk: > - clk_disable_unprepare(priv->bus_clk); > -err_can_clk: > - clk_disable_unprepare(priv->can_clk); > err_irq: > free_irq(ndev->irq, ndev); > err: > + pm_runtime_put(priv->dev); > + > return ret; > } > > @@ -910,12 +904,11 @@ static int xcan_close(struct net_device *ndev) > netif_stop_queue(ndev); > napi_disable(&priv->napi); > xcan_chip_stop(ndev); > - clk_disable_unprepare(priv->bus_clk); > - clk_disable_unprepare(priv->can_clk); > free_irq(ndev->irq, ndev); > close_candev(ndev); > > can_led_event(ndev, CAN_LED_EVENT_STOP); > + pm_runtime_put(priv->dev); > > return 0; > } > @@ -934,27 +927,21 @@ static int xcan_get_berr_counter(const struct net_device *ndev, > struct xcan_priv *priv = netdev_priv(ndev); > int ret; > > - ret = clk_prepare_enable(priv->can_clk); > - if (ret) > - goto err; > + ret = pm_runtime_get_sync(priv->dev); > + if (ret < 0) { > + netdev_err(ndev, "%s: runtime resume failed(%d)\n\r", > + __func__, ret); > + return ret; > + } > > - ret = clk_prepare_enable(priv->bus_clk); > - if (ret) > - goto err_clk; > > bec->txerr = priv->read_reg(priv, XCAN_ECR_OFFSET) & XCAN_ECR_TEC_MASK; > bec->rxerr = ((priv->read_reg(priv, XCAN_ECR_OFFSET) & > XCAN_ECR_REC_MASK) >> XCAN_ESR_REC_SHIFT); > > - clk_disable_unprepare(priv->bus_clk); > - clk_disable_unprepare(priv->can_clk); > + pm_runtime_put(priv->dev); > > return 0; > - > -err_clk: > - clk_disable_unprepare(priv->can_clk); > -err: > - return ret; > } > > > @@ -967,15 +954,45 @@ static const struct net_device_ops > xcan_netdev_ops = { > > /** > * xcan_suspend - Suspend method for the driver > - * @dev: Address of the platform_device structure > + * @dev: Address of the net_device structure This is just the device structure. K will modify in the next version of the patch . > * > * Put the driver into low power mode. > - * Return: 0 always > + * Return: 0 on success and failure value on error > */ > static int __maybe_unused xcan_suspend(struct device *dev) { > - struct platform_device *pdev = dev_get_drvdata(dev); > - struct net_device *ndev = platform_get_drvdata(pdev); > + if (!device_may_wakeup(dev)) > + return pm_runtime_force_suspend(dev); > + > + return 0; > +} > + > +/** > + * xcan_resume - Resume from suspend > + * @dev: Address of the net_device structure ditto K will modify in the next version of the patch . > + * > + * Resume operation after suspend. > + * Return: 0 on success and failure value on error */ static int > +__maybe_unused xcan_resume(struct device *dev) { > + if (!device_may_wakeup(dev)) > + return pm_runtime_force_resume(dev); > + > + return 0; > + > +} > + > +/** > + * xcan_runtime_suspend - Runtime suspend method for the driver > + * @dev: Address of the net_device structure ditto. K will modify in the next version of the patch . > + * > + * Put the driver into low power mode. > + * Return: 0 always > + */ > +static int __maybe_unused xcan_runtime_suspend(struct device *dev) { > + struct net_device *ndev = dev_get_drvdata(dev); > struct xcan_priv *priv = netdev_priv(ndev); > > if (netif_running(ndev)) { > @@ -993,16 +1010,15 @@ static int __maybe_unused xcan_suspend(struct > device *dev) } > > /** > - * xcan_resume - Resume from suspend > - * @dev: Address of the platformdevice structure > + * xcan_runtime_resume - Runtime resume from suspend > + * @dev: Address of the net_device structure ditto. K will modify in the next version of the patch . Regards, Kedar. Thanks, Michal This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. 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